Credits are used when you choose an AI-powered action in Boundless Ink. Manual writing, editing, organizing, uploading files, and managing your books do not use AI credits.
Your subscription includes a monthly credit allowance. When you use Muse, generate writing, analyze a manuscript, build or refresh AI-generated Story Bible data, create a cover, generate audio, or use another AI tool, the listed credit cost is deducted from that allowance.
Costs reflect how much work the AI has to do. A chat message reads a few sentences; a manuscript analysis reads your entire book.
Credits aren't a licence to a feature — they pay for the compute of one job. When you rebuild a Story Bible after adding five chapters, the AI reads the manuscript again and produces new records. When you regenerate a cover, it paints a brand-new image. That second run costs the same as the first because it's the same amount of work.
To keep re-runs down: finish a batch of chapters before rebuilding the Story Bible, and use the cover prompt helper (a couple of credits) to get the wording right before spending on a full image.
Monthly credits refresh on your billing date and don't roll over. Purchased top-up credits never expire and are only used once your monthly credits run out.